package com.atguigu.juc;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class ShareResource {
    private int num = 1;   //A:1 ; B:2 ; C:3
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();


    public void print5() {
        lock.lock();
        try {
            //1、判断
            while (num != 1){
                condition1.await();
            }
            //2、干活
                for(int i=1;i<=5;i++ ){
                    System.out.println(Thread.currentThread().getName()+"\t"+ i);
                }
            //3、通知
            num = 2;
            condition2.signal();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void print10() {
        lock.lock();
        try {
            //1、判断
            while (num != 2){
                condition2.await();
            }
            //2、干活
            for(int i=1;i<=10;i++ ){
                System.out.println(Thread.currentThread().getName()+"\t"+ i);
            }
            //3、通知
            num = 3;
            condition3.signal();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void print15() {
        lock.lock();
        try {
            //1、判断
            while (num != 3){
                condition3.await();
            }
            //2、干活
            for(int i=1;i<=15;i++ ){
                System.out.println(Thread.currentThread().getName()+"\t"+ i);
            }
            //3、通知
            num = 1;
            condition1.signal();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

}


/**
 * 多线程之间按顺序调用，实现A->B->C
 * 三个线程启动后，要求如下：
 * AA打印5次，BB打印10次，CC打印15次
 * 接着
 * AA打印5次，BB打印10次，CC打印15次
 * .....来10轮
 * <p>
 * * 1、 高内聚低耦合前提下，线程操作资源类
 * * 2、 判断、干活、通知
 * * 3、 多线程交互中，必须要防止多线程的虚假唤醒，也即（判断只用while，不能用if）
 * * 4、 注意标志位的修改
 */
public class ThreadOrderAccess {

    public static void main(String[] args) {

        ShareResource shareResource = new ShareResource();

        new Thread(()->{
            for(int i=0;i < 10;i++){
                shareResource.print5();
            }
        },"A").start();

        new Thread(()->{
            for(int i=0;i < 10;i++){
                shareResource.print10();
            }
        },"B").start();

        new Thread(()->{
            for(int i=0;i < 10;i++){
                shareResource.print15();
            }
        },"C").start();
    }

}
